<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            display: flex;
            margin: 0 auto;
            background-color: red;
            justify-content: center;
        }
        .box div{
            width: 200px;
            height: 200px;
            background-color:lightcoral;
            margin: 5px;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="d1"></div>
        <div class="d2"></div>
        <div class="d3"></div>
    </div>
</body>
</html>